Mars Reconnaissance Orbiter's (MRO) HiRISE instrument has transformed our view of Mars from a barren world to one of diverse and active landscapes.

In this enhanced color view we see erosion of the seasonal polar caps on Mars, which are made of carbon dioxide (a.k.a. dry ice). This erosion gives us "araneiform" terrain (various formations on the surface, such as "spiders," "caterpillars" and "starbursts."). (Which do you think is/are pictured here?)

"At least for me, before MRO, Mars was red and dusty everywhere. Now, we have all these images of a diverse and active planet: beautiful rock formations, dunes, flow features (possible evidence for water just below the surface), glaciers, and erupted geyser-like features -- so-called "spiders" -- in the north."